Because the core is way too low in order for it to work properly. Even a 7800GT OCed wouldn't be actually make a difference. All it does is to impress your friends until they pee in their pants because it set on fire.

No with older cards you can notice a diffrence. If I read right, than your saying to me that I didn't notice the frame rase in CSS with my TI 4200 when I was @ 20 to 32 in a hard rendering map...

Even my X1600Pro I notice a big diffrence in games when I overclocked. It just Depends on the overclock he gets. If he overclocked 5Mhz than you won't notice a thing but 50mhz or higher you can see some frame rates go up.

Anyways here is hes picture of hes current overclock. He's Stock speed is 270mhz -> 310mhz = 40mhz overclock. it shouldnt really be much faster in UT game that he has, but once he get's high he should see some games run faster

No with older cards you can notice a diffrence. If I read right, than your saying to me that I didn't notice the frame rase in CSS with my TI 4200 when I was @ 20 to 32 in a hard rendering map...

Even my X1600Pro I notice a big diffrence in games when I overclocked. It just Depends on the overclock he gets. If he overclocked 5Mhz than you won't notice a thing but 50mhz or higher you can see some frame rates go up.

Anyways here is hes picture of hes current overclock. He's Stock speed is 270mhz -> 310mhz = 40mhz overclock. it shouldnt really be much faster in UT game that he has, but once he get's high he should see some games run faster

Well duh he'll get more frames, but he asked if he would notice a difference in graphics. And the answer is no. He'll get more frames, but graphics wise...no, not really. If any, it would be very very very small.